And I will turn thee back, and leave but the sixth part of thee, and will cause thee to come up from the north parts and will bring thee upon the mountains of Israel. Ezekial 39:2, KJV
Both Young’s and Strong’s Concordances support the KJV translation which states that God while destroy 5/6th of Israel’s attackers (specifically, God states He will only leave/spare 1/6th).
ESV Reader Note: For the sake of easier reading, the ESV Bible rounds 5/6th to 85%. Although very close, 5/6th and 85% are not the same. 5/6th is equal to 0.8333…, while 85% is equal to 0.85.